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Advanced timing expertise and facilities for testing and evaluation

Future compact atomic clocks have the potential to provide precise timing to a variety of critical infrastructure services, such as energy supply, transport links, mobile communications, data networks and electronic financial transactions.  

State of the art systems are being developed spanning orders of magnitude in performance specification, from compact radiofrequency clocks up to larger, but much higher specification, portable optical clocks. Therefore, the capability to test and evaluate this wide range of systems, and the associated sub-components, is required to accelerate the commercialisation of this technology.   

For example, several quantum technologies (such as atomic clocks, gravimeters and magnetometers) depend on lasers that output very narrow spectral emission lines with stable optical power. Frequency or amplitude noise can result in sub-standard performance from these systems and so techniques for verifying performance against specifications are critical. This testing capability is currently under development and will directly benefit organisations developing the next generation of compact atomic clocks and the components required for their effective function.  

A new facility is being developed, within the Advanced Quantum Metrology Laboratory (AQML) at NPL, which has been designed for testing and evaluating quantum clocks and clock sub-components. The facility will produce stable and accurate reference signals at relevant frequencies from optical through to microwave and radiofrequencies. These reference signals will be traceable to global standards from links to NPL’s caesium fountain primary frequency standards and the UK’s national time scale UTC(NPL). End-users will be able to access the time and frequency reference signals.  

We plan to create evaluation facilities for radiofrequency and microwave clocks, lasers and optical clocks. In addition, test procedures with documented traceability routes will be established for evaluating the environmental sensitivity of clocks, covering temperature, humidity and magnetic field. Different techniques for measuring laser linewidth and residual intensity noise will be compared and standardised, and the output of this study used to prepare good practice guides for use in industry. 

Find out more about our ISCF projects

Find out more about our research on compact atomic clocks

Find out more about our research on optical atomic clocks

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Contact our quantum team

Case study

Characterising vapour cells for ultra-accurate atomic clocks